The present invention relates to a face plate for releasable attachment between a hammer and a hammer tip. In particular, the face plate attaches between the hammer tip and the hammer a size reducing machine.
Size reducing machines, like tub grinders, rotary hammer mills, vertical and horizontal feed machines, and the like, are used to process waste material. The machines consist of a large tub or drum containing a motor driven rotor that spins on a central shaft. A plurality of hammers attach to the rotor, and extend radially outward into the debris path. Hammer tips, or inserts, in turn, attach to the exposed face of the hammers. The edges of the hammer tips contact the debris. This impact in major part converts the material in the machine to debris sized to pass through a screen and out of the machine. The hammer tips are replaceable in view of the wear they experience during operation.
The conventional method for attaching a hammer tip to a hammer comprises inserting one or two bolts through a bolt hole in the hammer tip and hammer then securing the threaded end of the bolt with a threaded nut. Generally, this comprises the sole means of attachment. However, U.S. patent application Ser. No. 09/326,209 filed on Jun. 4, 1999 entitled SADDLE-BACK HAMMER TIP discloses a novel method for further securing the hammer tips to the hammers. Namely, the back of the hammer tip includes two opposing shoulder sections with a recessed section therebetween. The shoulder sections and the recess formed there between create a saddle-back for releasable integration with the hammer face.
During operation of the size-reducing machine, however, the hammer tips come into frequent and violent contact with the product under seeing size reduction. In addition to causing the hammer tips to wear, extreme hits to the hammer tips and damage the tips and in some cases damage the hammers. Additionally, the hammer tips can break and dislodge from the hammers. This leaves the hammers exposed to impact. In some cases the failure to timely replace the hammer tips can result in excessive wear, even to the point were the hammer tip wears all the way through again exposing the hammer to impact. It is not unusual to have to replace the hammers because of damage, dislodging, or excessive wear of the hammer tips. Replacing a hammer results in excessive downtime, increased costs in terms of parts and labor, and other disadvantages that increase the cost of operating the size-reducing machine.
Accordingly, a need exists in the art for a way to reduce damage to the hammers, and to more easily repair damaged hammers.
An object of the present invention comprises providing a face plate that will provide protection to the hammer in the case of import to the hammer tip.
These and other objects of the present invention will become apparent to those skilled in the art upon reference to the following specification, drawings, and claims.
The present invention intends to overcome the difficulties encountered heretofore. To that end, a face plate is provided for releasable attachment between a hammer and a hammer tip of a size-reducing machine. The face plate provides a buffer between the hammer and the hammer tip. The hammer has a body with a forward facing hammer face that aligns with the back of the face plate. The front of the face plate aligns with the back of the hammer tip. The hammer, hammer tip, and face plate contain aligned bolt holes for receipt of a securement bolt that releasably secures the hammer, face plate, and hammer tip.